THURSDAY, June 26 (HealthDay News) -- Sudden hearing loss may foreshadow a stroke by as much as two years,say Taiwanese researchers.

The researchers analyzed five years of follow-up data on 1,423 patients hospitalized for an acute episode of sudden hearing loss and found they were more than 1.5 times more likely to suffer a stroke than a control group of 5,692 patients hospitalized for an appendectomy.

The findings, published in the current issue of Stroke, haven't been duplicated in other research and should be interpreted with caution.

"To the best of our knowledge, no study has investigated the incidence or risk of cerebrovascular diseases developing following the onset of sudden sensorineural hearing loss," lead investigator Herng-Ching Lin, a professor at Taipei Medical University School of Health Care Administration, said in a prepared statement.

"But because this is the first time any association has been suggested, and because there were many limitations in the data, the results need to be interpreted cautiously until additional independent studies are performed," Lin said.

One limitation was the lack of a clear definition for sudden sensorineural hearing loss in the database reviewed by the researchers.

"Secondly, the database did not contain information regarding severity of hearing loss, extent of hearing recovery, tobacco use, body-mass index and the medical history of cardiovascular disease and atrial fibrillation -- all of which can contribute to stroke risk," Lin said.

Even so, the researchers recommended that all hearing loss patients have a comprehensive neurological exam and blood testing to assess their stroke risk.

More information

The U.S. National Institute of Neurological Disorders and Stroke outlines stroke risk factors and prevention.